Every field that aspires to science uses numbers to prosecute its business. If You Can’t Count It, You Can Publish It! So, numbers, particularly in the form of statistical analysis are a crucial part of science. Yet, as I’ve demonstrated numerous times in the Persuasion Blog, some science is mere sophistical statistics, those persuasive presentations of p < .0something, the rhetoric of research. The worse the science the better the persuasion, right?
Of course, this is just one fool’s opinion and he’s cherry picking examples to fit his argument. Show me something other than your sarcasm, Steve.
Okay. How about this demonstration of sophistical statistics.
We related the reluctance to share research data for reanalysis to 1148 statistically significant results reported in 49 papers published in two major psychology journals. We found the reluctance to share data to be associated with weaker evidence (against the null hypothesis of no effect) and a higher prevalence of apparent errors in the reporting of statistical results. The unwillingness to share data was particularly clear when reporting errors had a bearing on statistical significance.
This summary gives it up nicely. Three researchers reanalyzed the published statistics in 49 papers in either the 2005 issues of Journal of Personality and Social Psychology of the Journal of Experimental Psychology: Learning, Memory, and Cognition, two well respected psychology journals. These particular papers were chosen because another research team had contacted the authors of the studies in a previous project, merely asking for a copy of the datasets used in the publications. Some of the 49 authors provided the data, some didn’t. After waiting five years (5 years!!!), the current team pulled the studies and checked the results sections for errors and inconsistencies.
As the researchers noted in the Abstract they found that authors who would not disclose data had more errors of statistical analysis and that the tests of statistical significance were much more likely to be extremely close to the p < .05 level. Here’s a pie chart that displays errors by data shared or not.

Even among researchers who shared the data, there were errors in their analyses, but just eyeballing the differences between the two groups, you can see that folks who refused to share data (after five years!) made more of all kinds of errors. And, the differences are Medium to Large Windowpanes, 35/65 to 25/75 differences, so they are obvious, practical, relevant. What’s more, authors who did not share had data with marginal results; they were more likely to report p values at or near the traditional .05 alpha while authors who shared data found results with much smaller alphas (> .001). Here’s a bar chart to illustrate.

You can see that the gray bars represent authors who did not share and that they had more errors at or near .05 and .01, traditional, almost ritualistic, markers of effect. You can understand why they were reluctant to share. If you found results, but didn’t share your data, chances were good the results were small effects that you had to finagle to achieve even statistical significance. No wonder these authors found good reasons to withhold their data even after five years of waiting.
Oh, and if you’re not familiar with the publication ethics of publishing in these journals, you need to know that all authors have to sign a contract when they publish stating that they will share data when it is requested. This is not a matter of personal preference or taste; it is a professional standard of behavior with your signature of agreement and consent on it.
Authors who don’t share data are not doing good science. Their inaction violates both the letter and spirit of a contractual agreement they made when publishing. They obviously withhold data because they know they engaged in sophistical statistics and if anyone else ran the data, they’d expose the rhetorical research.
So, through a thoughtful research project on statistical analysis in peer review journals we actually learn a lesson about human nature and persuasion.
All Bad Science Is Persuasive!
Wicherts JM, Bakker M, Molenaar D (2011) Willingness to Share Research Data Is Related to the Strength of the Evidence and the Quality of Reporting of Statistical Results. PLoS ONE 6(11): e26828.
doi:10.1371/journal.pone.0026828